RESET PHONE
Well you need not to visit service center or any repair shop you can do it by yourself, its very easy.
OR
But always remember before resetting your phone you should take take BACKUP of your data because it will be deleted after resetting your phone.
RESET PHONE
- Go to settings -> backup and reset -> factory data reset - > reset device - > erase everything. (Always recommended)
- Turn off your phone, then press home button, volume up button and power button.